Oil cooler



o. n. H. BENTLEY OIL COOLER Filed March 27, `1941 aiented Jan. 26, i943 l Claim. 'Ihis invention, relates to oil coolers and relates more particularly to controls for preventing water from entering the oil lines of an oil cooler through which water for the cooling of the oil is circulated.

On ships utilizing steam turbines. it is customary to cool the oil for lubricating the turbine and its associated mechanism in an oil cooler through which water from the ship ushing system is passed in indirect contact with the oil for cooling same. It is customary to maintain water pressures from say 50 toV 75 pounds in the flushing systems. These 'pressures vary over a wide range depending upon the volume of water being used at any given characteristics are such that from to 25 pounds lubricating oil pressure should be maintained. Heretofore due to electrolysis, chemicals in the harbor Water, or erosion, leaks have developed in the water tubes in theoil coolers with the result the greater water pressure forced salt water into thev oil causing lubrication failure and often as a consequence, serious damage to bearings, shafts and rotors of the turbines.

This invention eliminates the dimculties which have previously followed the failure of oil coolers by providing in association with the cooler,vaI pressure regulator which maintains the water pressure in the oil cooler, lower than that of the oil pressure so that in case of a leakdeveloping in the water tubes, the oil ows into the water instead of the water into the oil, and by providing in association therewith, a pressure control for shutting down the turbine when the oil pressure as a result of an oil leak in the oil cooler, falls below a critical operating pressure.

An object of the invention is to prevent the indirect cooling uid of an oil cooler from entering the oil in case a leak develops in the cooler.

Another object of the invention is to prevent bearings and equipment which rotates therein, from being damaged as a result of oil leaks in an oil cooler.

The invention will now be described with reference to the drawing oi which:

Fig. 1 illustrates diagrammatically an oil cooler safety control system with elements thereof in section, embodying this invention, and

Fig. 2 is a transverse section through a comtime as for ilushing the decks. 'Ihe turbine.

and the outlet l for cooling water connections. The partition 3 separates the inlet l and outlet B and provides that the water ow the length of the cooler through one tube Ii illustrated and back again through the other tube 6 illustrated. The oil for lubricating the bearings of the associated turbine passes through the tube 9 into the cooler 5 and passes from the cooler through the tube I0; flows back and forth between the bames i in contact with the outer surface of the tubes B, to the bearings to be lubricated.

'I'he oil cooler illustrated is of well known construction and may contain a large number of water tubes.

The branch tube Il carries oil from the tube 9 into the pressure regulating valve I2 which oil contacts the upper side (facing the drawing) `of the diaphragm 'I3 and depresses same in accordance with the oil pressure. I'he depression of the diaphragm I3 is opposed by vthe bronze coiled spring I4 which is in contact with the underside of the diaphragm. Water from the ilushing system is directed through the tube I5 into the water inlet I6 of the valve I2 and past bined pressure reducing and shut-oil valve which the valve piston il in contact with the underside of the diaphragm I3 and thence through the outlet I8 and tube I9 into the inlet 1 of the oil cooler 5. Water from the oil cooler passes out through the open tube 20 for discharge into the sea.

The constants of the pressure regulating valve I2 are so proportioned that the piston Il is adJusted relative to its seat 2| by the oil pressure acting upon the upper side of the diaphragm I3 so that the pressure of the water passing the piston Il is maintained about, for example, a pound below the oil pressure. Then if for any reason a leak develops in a water tube 6 due to the pressure differential, oil ilows inta the tube t into the water in the cooler 5 instead of vice versa as has always occurred in the past with the result not only that the oil is not cut by the 4 salt water with resulting bearing damage, but vthe pressure in the oil lines drops and actuates the additional safety control for shutting f lever 21 has the lower extension 22 which normally extends as illustrated, in contact with the upper end 22 oi the lever 22. The lever 22 is pivoted at 2i to the eittension 22 from the steam valve 22. The piston rod 22 of the valve 32 is connected at its outer end to the lever 22 between its ends, and at its inner end to the valve piston 22. The spring 22 exerts pressure against the piston its seat 21. The steam valve 22 has the steam inlet 22 for connection to the steam supply source, and has the steam outlet 22 for connection to the turbine or other mechanism to be controlled.

A leak in a water tube 2 in the cooler 2 will vcause oil to enter the water and will cause the 32 against its seat 21 to shut ofi the supply of steam to the turbine.

The valve 22 of Fig. 2 may be used in the system of Fig. l to combine the functions of the valves I2 and 22 of Fig. l in a single structure. The lower portion of the valve 22 below the diaphragm 2| is similar to that of the valve I2 previously described in that the water through the inlet I2 enters the valve and passes the piston to contact the lower surface of the diaphragm 22 before it passes from the valve through the outlet I2. Oil from the discharge tube I2 passes through the branch tubes il into the valve 22 in contact with the upper side of the diaphragm 2li. The piston 22 ton 22 of the valve 22 of Fig. l extends through the stuling' box 22 which prevents the escape of the oil around the piston 22. The lever 21 is similar to that of the lever 21 of Fig. 1 except that its extension 22 of Fig. 2 extends upwardly to engage the extension 22 oi the lever 22, the extension of Fig. 2 being shaped to be engaged against the extension 22 when the oil pressure is normal.

When the oil pressure falls below the critical operating pressure. the diaphragm 22 moves upwardly (facing Fig. 2 of the drawing) so that the piston 22 moves the lever 21 to cause the extension 22 to become disengaged from the extension 22 of the lever 22 to cause as in the case of the 22 tending to force it against' The spring $2 in the steam valve 22 then forces the piston A which corresponds to the pisasoaaae valve 22 the stein to be shut off by the associated i valve 22.

Prior to such time as the oil pressure falls below the critical point, the oil pressure on the upper side oiv the diaphragm 22 moves the diaphragm to cause the piston I1 to maintain a lower water pressure to the oil cooler, as pre` viously described in connection with the valve I2 of Fig. l. Oil pressure variations above the said critical operating pressure would not be sufcient to disengage the extension 22 of the lever 21 from the extension 22 of the lever 22, to shut od the steam supply to the turbine.

It is seen that the water pressure control mechanism and the steam control mechanism cooperate in that the water pressure control mechanism permits the oil to leak outwardly in case a leak develops in a water tube in the cooler instead of the water being forced into the oil as in the past, and in that the leaking of the oil causes the oil pressure to drop to actuate the steam control mechanism.

While the invention has been described in connection with oil coolers for steam turbines, using water for the cooling of the oil, other iiuids may be used in association with other mechanisms.

While embodiments of the invention have been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement l of apparatus illustrated, as modifications thereof may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is:

A pressure control valve for a liquid cooler, comprising a diaphragm; means forming a passage for conducting a liquid to be cooled in contact with one side of said diaphragm; means forming an inlet and an outlet passage for conducting 'a cooling liquid into said valve, in contact with the other side of said diaphragm, and. from said valve; a piston attached to said diaphragm; means in said inlet passage forming a seat for said piston; a spring for biasing said piston towards contact with said seat; a shut-0H valve for closing ofi the supply of actuating fluid for a machine, and means including means connected to said diaphragm for closing said shut- 0H valve when the pressure of the liquid to be cooled against said one side of said diaphragm falls below normal.

OLIVER D. H. BENTLEY. 

